Opiate dependent persons who are successfully engaged in the treatment of their primary drug of addiction often continue to use other drugs such as nicotine. With the high prevalence of smoking in this population, treatment providers are recognizing that a disproportionate number of those they help recover are now dying of smoking-related illnesses including cancer. Recent studies indicate that persons enrolled in methadone maintenance treatment programs are interested in receiving smoking cessation treatment, but success with standard behavioral and pharmacologic treatments have been disappointing for this population. New hope for dramatic improvement in cessation outcomes now exists with the recent FDA approval of varenicline tartrate, a nicotinic receptor partial agonist. The long-term aim of our proposal is to advance knowledge and produce interventions to help achieve optimal dissemination of smoking cessation strategies for persons with the dual diagnosis of opioid dependence and nicotine dependence. The design of this proposal builds on lessons learned from the successful recent completion of randomized clinical trial of a nicotine replacement smoking cessation intervention based in methadone programs. In the current proposal, we directly compare two forms of pharmacotherapy, combination nicotine- replacement-therapy versus non-nicotine-replacement therapy with varenicline, and compare these against varenicline-placebo. Using this three-group design, we will enroll 602 methadone- maintained cigarettes smokers from five methadone treatment programs in Rhode Island. The Specific Aims are: A.1. PRIMARY AIM To perform, in the setting of a methadone maintenance program, a randomized clinical trial to determine whether varenicline, a nicotine receptor partial agonist, leads to a higher rate of smoking cessation than combination nicotine replacement therapy which combines nicotine patch prescription plus ad libitum nicotine gum delivery. We hypothesize that the 6-month post- treatment 7-day point prevalence quit rates will be 20% and 10% in the two active treatment groups, versus 2.5% in a varenicline-placebo arm. A.2. SECONDARY AIMS a) To test the effects of the treatments on the key construct variables of our theoretical model including smoking urges, withdrawal symptoms, reinforcing effects of smoking. b) To test the effects of the treatments on methadone treatment outcomes including retention in methadone maintenance, methadone dose changes, and continued use of illicit drugs as measured by urine toxicological analyses. PUBLIC HEALTH RELEVANCE: Methadone-maintained smokers represent an important and large population of long- term, highly dependent smokers. This application compares, in the methadone setting, two forms of pharmacotherapy, combination nicotine-replacement-therapy versus non- nicotine-replacement therapy with varenicline tartrate, a recently approved nicotinic receptor partial agonist. With close to one million methadone treatment entries per year in the United States, this research can have a meaningful public health impact addressing a high-risk population that would otherwise be difficult to reach.